The product, which is made from mung beans, was created to 'to scramble and taste just like eggs' - but with a lower environmental footprint.
A JUST spokesperson told Plant Based News: "We had a fun visitor at JUST HQ this week - and have a new fan of JUST Egg."
Posting on social media about the product, Moby said: "Visiting @justforall and eating my first ever vegan omelet (actually my first ever omelet, as I went vegan in 1987 and have never had an egg omelet...)!
"I'm really, really impressed with the activist fueled entrepreneurialism here.
"Ps, the omelet was delicious."
Vegan JUST Egg
JUST Vegan Egg is currently available in Veggie Grill outlets in the States, in some Hong Kong outlets, and at the Grand Hyatt Singapore hotel.
It was supposed to launch on online retailer Jet in August (though at the time of writing, does not appear to be available on the site).
Earlier this Summer, it was announced that JUST had struck a distribution deal to bring the highly-anticipated product to Europe - though no timeline has been given yet for its arrival.